: The above link takes you the manual for this model series. This unit is for when you have a tankless coil plus a hydronic zone or two. In brief, T, TV and Z are in the 24VAC "loop". Around the "loop" it goes: [24 VAC XFRMR] to "Z" to ["1K Relay" (Low Limit/Circ. & High Limit Contacts)] to "T" to [low voltage T-stat] to "TV" to [24 VAC XFRMR]. If you want additional zones they want you to use R845A relay modules. Let me know if you need anything else, or if you can't get the PDF file via the link. - Bob

My existing boiler has a tankless coil and a honeywell aquastat L8124L. I will be switching to an indirect hot water system by adding another zone and a Peerless Partner 60 gal. tank. Can I still use the L8124L as my boiler control after the tankless coil is disconnected?